Lentil & Porcini Mushroom Shepherd's Pie

Add the potato to the saucepan of boiling water and cook until soft when pierced with a knife, 10-15 minutes. Drain well and return to the saucepan. Add the salt, milk and 1/2 the butter to the saucepan. Mash with a potato masher or fork until smooth. Stir through the grated Parmesan cheese. Season to taste with salt and pepper.

While the potato is cooking, heat the remaining butter and a drizzle of olive oil in a large frying pan over a medium-high heat. Add the onion, carrot and a pinch of salt and cook, stirring, until softened, 6-7 minutes. Add the garlic (reserve a pinch for the veggies), rosemary and thyme and cook until fragrant, 1 minute.

While the veggies are cooking, preheat the grill to high. Add the tomato paste to the frying pan with the veggies and stir to combine. Add the porcini mushrooms (roughly chop any big pieces) and porcini soaking liquid (leave any gritty bits at the bottom of the jug or bowl), lentils and vegetable stock. Simmer until thickened slightly, 2-3 minutes. Season to taste with salt and pepper.

Transfer the lentil mixture to a medium baking dish and top with the Parmesan mash. Run a fork over the mash to create an uneven surface, then place the pie under the grill. Cook until the top has browned slightly, 5-10 minutes. While the pie is grilling, trim and halve the broccolini lengthways. Wash the frying pan and return to a medium-high heat with a drizzle of olive oil. Add the broccolini and a splash of water and cook, tossing, until tender, 5-6 minutes. Add the reserved garlic and the baby spinach leaves and cook until wilted, 1 minute. Season with a pinch of salt and pepper.